Contagious Ecthyma

This a zoonotic disease meaning that it affect humans as well. Its occupational hazard for veterinary doctors.
This condition is similarly referred to as orf, contagious pustular dermatitis and sore mouth. It is an infectious disease of sheep and goats with the skin of the lips most commonly affected. The disease is more severe in young animals and more severe in sheep than goats.

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Animals under extensive management are more prone to infection than those under good husbandry and management systems.
Man may occasionally contract the disease. In Nigeria the disease is more common in West African dwarf goats and sheep, with the disease seen more during the rainy season than in the dry season. The disease is worldwide.
Its also affects dogs occasionally, here is picture proof....

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Aetiology

The pox virus (paraoxvirus) that is related to pseudocowpox and bovine popular stomatitis viruses has been considered as the aetiologic agent.

Transmission and Predisposing Factors

Close contact is the main source of infection for others. Thus animals incubating the disease upon addition to other flocks may spread the disease to the flock. Other predisposing factors include:
Allowing animals to roam about in town and village settings as to be in contact with infected ones;

1. Addition of newly purchased animal(s) to flocks without prior isolation to determine their health status;
2. Burrowing breeding males that may be infected or incubating the disease;
3. Sending an ewe or doe to an infected flock for mating;
4. Grazing animals of different backgrounds from different flocks on a common communal grazing land and the subsequent interaction of infected and susceptible ones from different flocks;
5. Purchasing of animals for fattening, especially as it happens in preparation for religious festivals;
   Also by purchasing rams and/or bucks for religious festivals and adding them to regular flocks in the house before the time of the festivals.

Clinical Signs

The incubation period is 5 to 8 days. The first thing that might be noted is the development of few raised spots on the lips of affected animals and is wart like. This is followed by papules, macules and vesicles that coalesce to give a picture of large lesions on the mucosal surface of the mouth. Both upper and lower lips may be affected. These lesions look as moist scabs. When they are removed or break on their own, they leave raw bleeding wounds.
As the condition progresses, pus develops in the vesicles following secondary bacterial infection. The pustules then encrust to leave large scabs. The dermal tissue proliferates, thereby producing verrucose mass under them.
Occasionally, lesions may be observed at the interdigital region and around the coronet. Ewes and does nursing lambs and kids respectively may develop udder lesions. It is not unlikely to see lesions on the gums of infected animals.
Affected animals may be anorexic and exhibit white foamy discharges from the mouth. Animals may later find it difficult to feed even if the appetite is restored. Severely affected animals lose weight. Where leg lesions appear slight lameness may be seen.
It is common to see scabs falling down with the tissues healing normally without scar formation. There may also be mild mastitis in situations where the udder is affected.
In man the disease is seen mainly on the hands and face with the lesions being more proliferative resulting in distress.
Also its affect humans as have said ealier here is picture proof.

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Pathology

The lesions as described above are characteristic. The lesions are confined to the mouth parts or areas of the skin in neighborhood to the mouth. Secondary bacterial infections may result in ulcerative stomatitis, reticulitis, and enteritis with necrotic lesions seen in the lungs, and liver.

Diagnosis

This is by history, presence of any of the predisposing factors, clinical signs and serology to identify the antigen in the vesicular lesions.
The disease should be differentiated from sheep and goat pox and ulcerative dermatosis among others. The rate of spread of the disease can be suggestive. The sporadic nature of the occurrence in the area can be of help. The disease should be differentiated from dermatophilosis, tick bite dermatitis and wart among other diseases.

Treatment and Control

There is no specific treatment except supportive medication. The disease is transmissible to man, especially sheep and goats’ handlers and veterinarians. Thus protective clothing like gloves should be worn while handling such cases.
Control is by the strict observance of the predisposing factors. A vaccine at commercial level is available for highly valuable animals and should be used with caution as not to contaminate uninfected premises and flocks.

Here are my references..
Merck's veterinary manual 2016 edition
Large animal veterinary textbook
DYCE, veterinary anatomy text book
Ruminant medicine made easy

Its your veterinary steemian. Nice having you guys. Hope you gained today. See you in my next post.